This invention relates to an improvement in the assembly of spring brake actuators.
Spring brake actuators have traditionally included housing members that are connected together by bolted clamp bands. Piston type spring brake actuators have typically included an outer housing member connected to a central housing member by a removable clip, or other holding structure.
More recently, brake actuators have included housings that are connected together by inelastically deformed portions that prevent opening of the prior bolted clamp bands. The inelastically deformed type of brake actuators have enjoyed wide commercial success, and have become standard in the industry. Other types of tamper resistant brake actuators have been also been proposed.
There are some aspects of the tamper-resistant spring brake actuators that could be improved, however. One such aspect is the method of deforming the housing members together. In the prior art, a central housing has typically been formed with a port for connection to a source of pressurized air. The ports have typically extended radially outwardly of the nominal body of the central housing. The tools which inelastically deform the housing members have typically moved into contact to deform a housing member. Typically an outer end of the housing member to be deformed has been deformed radially inwardly. The central housing has been formed of a minimum axial length for this type of brake actuator, as it has been necessary to ensure that the tools which deform the housing members do not come into contact with the ports. If the deforming tools do contact the ports, damage can occur. Thus, the prior art spring brake actuators which have utilized deformed housings have included central housing members of an undesirably long length.